This invention relates to infrared heaters such as employed to heat large spaces such as garages, warehouses, and the like from an overhead location.
Many large spaces are heated by so-called unit heaters. A unit heater is one that is self-contained in that a single unit includes a burner, typically the controls therefor, and some sort of heat exchange device for rejecting heat from the gases of combustion generated by the burner to the surrounding environment. One type of unit heater causes the hot gas of combustion to be passed through an elongated tube or the like before being expelled from the structure in which the heater is mounted. While some of the heat rejected to the environment is by means of conduction or convection to the air in which the tube is located, the primary means of heat rejection is by infrared radiation from the exterior surface of the tube.
In the usual case, such infrared heaters are mounted at an elevated location in the structure that they are intended to heat, frequently being in the range of 10-20 feet above the floor of the structure. Reflectors may be employed to direct infrared radiation downwardly toward the floor.
Because of the size of infrared heaters as well as the fact that they are mounted at a considerable distance above the floor, installing the heater and adjusting it for proper operation can be cumbersome tasks. In some cases, adjustment of the heaters is made difficult by parts of the structure in which the unit heater is mounted. For example, if a heater is mounted near a wall, access to the burner enclosure may be impeded by the wall.
Furthermore, many such infrared heaters are incapable of being adjusted properly during operation thereof. In some of these heaters, access to the controls can be achieved only by opening the burner enclosure which, in turn, may alter the characteristics of the incoming combustion air stream while the enclosure is open. Consequently, after the adjustment has been made, and the enclosure reclosed, the resulting change in combustion air patterns may alter operation of the heater to the point where it is not in proper adjustment. As a consequence, it may be necessary to open and close and reopen and close the enclosure for the burner during the adjusting process to repeatedly make adjustments until an adjustment that works properly with the enclosure closed is found by trial and error.
The present invention is directed to overcoming one or more of the above problems.
It is, therefore, the principal object of the invention to provide a new and improved infrared heater. More specifically, it is an object of the invention to provide such an infrared heater than may be easily installed and serviced, including adjustments, and which is of economical construction.
In one embodiment of the invention, there is provided a burner and fan enclosure for an infrared heater which includes a generally rectangular low pressure housing having a top wall, a bottom wall, opposed side walls and spaced rectangular panels. An air inlet is located in one of the walls and a burner outlet is located in one of the walls. A high pressure housing is located within the low pressure housing and has a side aligned with the burner outlet. An elongated burner tube is located within the high pressure housing and has opposed ends. One end of the burner tube extends through the burner outlet. A turbulator plate has plural openings therein arranged about a generally central opening and is located at or integral with the side wall having the burner outlet with the generally central opening receiving and supporting one end of the burner tube. A fuel manifold is also located within the high pressure housing adjacent the other end of the burner tube and a fuel orifice is in fluid communication with the manifold and aligned with the other end of the burner tube for directing fuel thereinto. A fan is disposed within the low pressure housing and is in fluid communication with the interior thereof. A gas control valve is located within the low pressure housing and has an outlet connected to the manifold.
As a consequence of this construction, when the low pressure housing is open to achieve access to the gas valve for adjustment purposes, the air stream to the burner within the high pressure housing is unchanged, allowing adjustment of the system during operation to avoid repetitive, trial and error adjustments.
According to another aspect of the invention, there is provided a low pressure housing, a burner outlet and high pressure housing as before. Also provided is a burner tube within the high pressure housing having one end extending toward the burner outlet. A fuel manifold is also located within the high pressure housing along with a fuel orifice in communication with the manifold and aligned with the burner tube for directing fuel thereinto. A gas control valve is disposed within the low pressure housing and is accessible through either of two removal side panels forming part of the low pressure housing and a rotary union is provided to interconnect the control valve outlet and the manifold.
This facet of the invention allows the gas valve, during installation, be twisted to face either of the side panels of the low pressure housing so that access may be achieved therethrough on either side of the enclosure. Consequently, a wall or other structure blocking access to one side panel can be avoided simply by rotating the gas valve within the housing at the time of installation so that its control parts are facing the opposite side panel which may be free from obstruction.
A preferred embodiment contemplates that there be two spaced, downwardly extending flanges on the top wall extending between the side walls of the low pressure housing and that there be two generally Z-shaped flanges on each of the side walls of the low pressure housing extending between the top and bottom walls. The side panels include reentrant flanges on the tops and sides thereof and the low pressure housing further includes at least one hook-like element at or near the bottom wall of the low pressure housing adjacent each side panel. Thus, the side panels may be easily fitted to the low pressure housing and removed therefrom. During an adjustment process, a side panel that has been removed may be suspended by the hook-like element, thereby providing easy access to the same when reinstallation of the side panel is required at the completion of the adjustment process.
In one embodiment of the invention employing an apertured turbulator plate, there are plural openings about a central opening. Preferably, the plural openings are apertures in the turbulator plate.
In one embodiment of the invention, turbulating vanes are located in the apertures.
In addition, the plural openings may be located radially outward of the central opening and have respective slots extending to the central opening. Portions of the turbulator plate between the slots are twisted on the turbulator plate to define the vanes between adjacent slots.
Other objects and advantages will become apparent from the following specification taken in connection with the accompanying drawings.